Steam separation driers using the centrifuge effect in tubes have the advantage of small bulk in relation to the flow of steam to be treated and can therefore be disposed in steam flows directly at the output of the moisture generating devices such as expansion turbines thereby dispensing with, or reducing, lengths of piping for conveying wet steam.
Such piping is subjected to erosion-corrosion phenomena and clearly a reduction in its length is desirable. These driers produce dry steam with a low residual water content of about 0..1% and consequently reduce to a minimum, the volume of water retained in the steam circuits, which water is liable to become vaporized during steam pressure drops thereby lowering the temperature of the steam and reducing its thermodynamic efficiency. However, the separated water is still mixed with steam and even if it is introduced into a chamber which allows separation by gravity, separation is incomplete. The water which trickles down still withdraws a quantity of steam which is lost from the thermodynamic cycle. This reduces the efficiency of the downstream equipment (expansion turbines, heat exchangers). The steam which rises in this chamber still contains droplets of water; it is therefore difficult to use without danger, in particular of corrosion, unless expensive stainless steel tubing is used.
The present invention aims to remedy the above drawbacks and to provide a vertical separator which is capable of producing firstly dry steam with a low residual water content and secondly an extra fraction of steam from which the maximum of residual water has been removed and which contains only a few percent of water, which steam can be used in thermodynamic circuits without causing appreciable erosion-corrosion in the tubing. The invention is applicable to fluids other than H.sub.2 O.